Air quality models incorporate complex hydroxyl radical chemistry that couples fast and slow reactions, creating significant numerical stiffness and stability challenges for standard ordinary differential equation solvers.
The claim specifically addresses numerical stability problems caused by hydroxyl radical chemistry in air quality models. Papers [2] and [3] directly discuss the mathematical stiffness of atmospheric chemical kinetics involving OH and related species, and the challenges they pose for numerical integration and solvers in chemical transport models. The rest of the papers examine various specific reaction mechanisms or unrelated topics but do not contradict the premise that OH chemistry contributes to model stiffness. Therefore, the claim is supported by the evidence.